An improved clip

Abstract

A clip 10 for securing a cable in position relative to a support structure is a unitary member arranged to comprise a pair of opposed legs 12 joined by a central portion. Each of the pair of opposed l

Description

The present invention relates to an improved clip for use in securing cables, pipes and similar items to a support structure such as a cable tray, basket, Unistrut support or similar. In any building, it is typically necessary to run cables, pipes and the like from one point to another. Herein, for ease of reference, the term cable will be used, but it should be noted that embodiments of the invention may also be used with pipes carrying a range of fluids, such as water, gases, fuel, chemical feedstocks, or lubricants. The cables may be used to carry power, such as HV cables, or singalling, including copper and fibre-optic cables. In the prior art, it is known to run lengths of cable in a suitable cable tray. Such cable trays can be provided in a suspended manner, where they are arranged to hang from a ceiling structure, with the cable tray sometimes concealed behind a false ceiling. They can also be fastened to a wall, with the cables fastened thereto. A known problem with such prior art structures relates, in particular, to the means by which cables are fastened thereto. It is known to use cable ties formed from a plastics material to secure the cables in position. This provides a quick and simple, low-cost, solution to securing cables to the support structure. Figure 1 shows a known cable tie 1, formed from a plastics material. A detailed description is omitted since these are well known. However, cable ties 1 formed from a plastics material have an unsatisfactory performance in the event of fire. A particular problem is encountered if a cable run is arranged above a doorway or other access point. In the event of a fire, the plastics material cable tie 1 melts, resulting in the previously fastened cables falling into the doorway, posing an additional and potentially deadly hazard for firefighters. There is a move to prohibit the use of cable ties of this sort. One solution proposed is the use of metallic cable ties in place of those formed from a plastics material. Such metallic cable ties are typically formed from stainless steel, since they are corrosion-resistant and durable. Such a cable tie 2 is shown in Figure 2. Again, a detailed description is omitted since these are well known. However, metallic cable ties 2 introduce problems of their own. Firstly, they are significantly more expensive than the plastics alternatives. Secondly, they can have razor-sharp edges, which require careful handling to avoid injury to the installer and to avoid damage to the cables which they are fastening. In particular, if any excess length is trimmed, after fastening, the resultant edges can be particularly sharp, especially if a customised tool, which rounds off sharp edges, is not used. Use of either the prior art cable ties 1, 2, can result in the need to trim excess material. The problems with the metallic tie 2 has been alluded to, but in both cases, the residue needs to be collected and, where possible, recycled. This creates additional problems. One of which is that stainless steel is not attracted to magnets, meaning that separating such waste from other types can be problematic. A further attempt to address the problems in the aforementioned cable ties is through the use of a cable cleat. Such a known cleat 3 is shown in Figure 3. Although it addresses some of the problems already mentioned, it introduced additional problems of its own. As can be seen, the cleat 3 is far more substantial than the previous solutions. In use, the cleat must be anchored to a suitable support via the addition of a suitable fixing through aperture 3c. The cleat comprises a hinge 3a, allowing it to be opened to receive one or more cables therein. Once the cable or cables have been introduced, the cleat is fastened in a closed configuration by means of fastener 3b, which comprises a nut and bolt and allows the cleat to be securely fastened and thereby retain the cable in place. However, the time involved in fitting and then fastening the cleat 3 is substantial and increases an installation time significantly compared to the use of cable ties 1, 2. Additionally, the unit price of a cleat is significantly higher than that of cable ties 1,2. There therefore exists a need to provide alternative cable retention solutions which address some or ideally all of the shortcomings of the aforementioned prior art solutions. According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. According to a first aspect of the present invention, there is provided a clip for securing a cable in position relative to a support structure, wherein the clip is a unitary member arranged to comprise a pair of opposed legs joined by a central portion, wherein each of the pair of opposed legs comprises a hook for engagement with the support structure and the central portion comprises a projection, whereby in the event of the projection being crimped, each respective hook engages securely with the support structure, thereby securing the clip, and hence the cable, in position, relative to the support structure. In an embodiment, the hook is provided with a lug for engagement with a corresponding aperture in the support structure, such that after crimping, the lug is securely retained in the corresponding aperture. In an embodiment, the clip is formed from a metallic material. In an embodiment, the metallic material is stainless steel. In an embodiment, the projection comprises a curved portion extending from a profile of the clip, the curved portion defining a volume, which, upon crimping, tends towards zero. According to a second aspect of the present invention, there is provided support structure for use with the clip of any preceding aspect, wherein the support structure comprises at least a first pair of slots arranged to receive the opposed legs of the clip and a second pair of slots, aligned with the first pair, the second pair being arranged to receive a lug provided on the clip. In an embodiment, the support structure is a cable tray or a vehicle chassis. According to a third aspect of the present invention, there is provided method of securing a cable using the clip of any preceding aspect, comprising the steps of: a) positioning the cable relative to the support structure at a desired location; b) placing the clip atop the cable and loosely engaging the hooks with a feature of the support structure; c) crimping the projection such that the clip securely engages with the support structure and so holds the cable firmly in place. Although a few preferred embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example only, to the accompanying diagrammatic drawings in which: Figure 1 shows a prior art cable tie of plastics material; Figure 2 shows a prior art cable tie of metallic material; Figure 3 shows a prior art cable cleat; Figure 4 shows a clip according to an embodiment of the invention; Figure 5 shows a typical installation using a clip according to an embodiment of the invention; Figures 6a and 6b show other typical installations using a clip according to an embodiment of the invention; and Figures 7a to 7f shows various steps in the installation of a clip according to an embodiment of the invention. Figure 4 shows a perspective view of a clip 10 according to an embodiment of the invention. The clip 10 is of unitary construction and is formed from a single strip of stainless steel, which has been processed to remove defined portions and then bent into the shape shown. The clip 10 comprises three major portions which include a pair of relatively elongate legs 12, which are disposed to face or oppose each other, whereby the legs are disposed either side of a projection 11, which forms a central portion of the clip. At the end of each leg 12 is a hook 13. The hook is formed by the selective removal of material from the strip which forms the clip 10. In a particular embodiment, the uppermost portion of the hook 13 comprises a relatively small projection or lug 14 which serves as a locator in certain implementations. Figure 5 shows a perspective view of one particular implementation of an installation including the clip 10. In this installation, a cable 20 is to be secured in position relative to a support structure 30. The support structure 30 is a Unistrut style which comprises an elongate member defining a generally U-shaped conduit 31. The support structure 30 is typically fastened to a wall, ceiling or other structural surfaces via fixing apertures 32. The outer exposed edges 33 of the conduit are curved inwards towards the interior of the conduit and it is this feature which allows the clip 10 to be fastened thereto. As can be seen in Figure 5, the cable is brought into position and the clip 10 is placed atop the cable, so that the two elongate legs essentially surround it and are placed into the conduit 31. The clip 10 is then moved so that the hooks 13 are positioned below the curved edge 33 of the support structure 30. In order, then, to secure the clip 10 and cable 20 firmly in position, it is necessary to crimp the projection 11, by applying a crimping or crushing force thereto, such that the gap beneath the projection 11 is closed, tightening the clip 10 in relation to the cable 20 and effectively causing the hooks 13 to enter the gap formed by the curved edges 33 of the support structure 30. In this way, the cable 20 is held firmly in position by the clip 10, which now engages securely with the support structure in a manner which does not permit movement of the cable. The crimping or crushing force may simply be provided by a pair of pilers or similar. Alternatively, a custom tool may be provided. Since the material of the clip 10 is workable, the force required to crimp the clip is not excessive and can easily be applied by hand. However, once crimped, the clip is essentially semi-permanently attached and is not likely to move under normal operating conditions. In this context, “semi-permanently attached” means that the clip, once fitted, will not typically work loose or release the cable under normal operating conditions, but it can be removed as the result of a deliberate action to remove it. This ensures that the cable 20 is held securely in position in all circumstances. Unlike the prior art referenced, the clip 10 will not melt in a fire situation. It does not require trimming and presents no sharp edges to an installer. It includes no fastenings, such as nuts, bolts or screws, and so does not experience issues caused by vibration which may result in such prior art fastenings working loose. Additionally, the clip is substantially tamper-proof, in the sense that the clip can not be casually removed; instead, a positive action is required in order to remove the clip, once crimped. Figure 5 illustrates just one of the many support structures to which the clip can be attached. The versatility of the clip 10 is illustrated by Figures 6a and 6b which show different support structures with which the clip 10 can engage. Figure 6a shows the clip 10 in use with a basket tray 40. Basket trays are known in the art and comprise a web of interconnected elongate metal members, forming said basket. The clip 10 is arranged, as shown, to engage with one of the members and so secure the cable in place. The placement of the clip and the crimping operation is as described previously. Figure 6b shows the clip in use with a cable tray 50, The cable tray, as known in the art, is an elongate conduit, typically have a generally flat bed to accommodate cables. Two elongate walls are typically provided at outer edges of the tray. The flat bed includes a number of apertures. In prior art installations, cable ties, described earlier, are threaded through the apertures and fastened to secure cables in place. When used with the clip 10 according to an embodiment of the invention, the hooks 13 are introduced into one or more such apertures and then the crimping operation acts to secure the clip and hence the cable in place. Figure 7 shows the use of a clip 10, combined with a complementary cable tray 60, specifically designed to cooperate with the clip 10. Advantageously, the cable tray 60 is compatible with prior techniques of cable fastening e.g. using cable ties. As such, only one type of cable tray is required to be stocked and if no clips 10 are available or required, cable ties may be used instead. However, the advantages mentioned herein are only achieved via use of clip 10. Figure 7a shows a detail of a section of a cable tray. The entire tray may be up to several metres long and several tens of centimetres wide. In terms of dimensions, the cable tray 60 resembles the profile of known cable trays, with the arrangement of the apertures in the bed of the tray being a distinguishing feature. In Figure 7a, various slots 61,62 are shown. These are arranged to cooperate with the clip 10. A first pair of relatively long slots 61 are arranged in a parallel formation, the distance between them matching the distance between the legs 12 of clip 10. A second pair of smaller slots or apertures 62 are arranged to align with, and at an end of, the longer slots 61. The means by which these slots cooperate with the clip will be described in the following by reference to Figures 7b to 7f. Figure 7b shows the cable tray 60 with a cable 20 placed in position to be secured. As can be seen, the cable 20 has dimensions which permit it to sit approximately between the pair of elongate slots 61. Figure 7c shows a plan view of how the clip 10 is introduced into position. It is placed atop the cable, with each of its legs 12 entering one of the slots 61. It can be seen that the dimensions of the clip 10 and the slot 61 are arranged to substantially match, so that the clip sits easily and without difficulty in the slots 61. Figure 7d illustrates the next step, whereby the clip 10 is slid in the direction of the arrow shown, towards the pair of smaller slots 62. The clip moves freely in this configuration, Figure 7e illustrates the crimping operation applied to projection 11 at the top of the clip 10. The projection 11 is crimped or crushed, thereby tightening the clip in position. The lug 14, positioned on an upper surface of the hook 13, is dimensioned and positioned to sit in the small slots 62 in this position and once the crimping operation has competed, the lugs 14 are located securely in the small slots 62. This has the effect of improving the security of the clipping operation. The cable 20 is now securely held in place. The clip will not slip from its position, due to the lugs 14 being retained in small slots 62. The crimping operation ensures that the cable 20 is held snugly and securely and permanently in place. In this context, “permanently” means until such time as an operative decide to take positive steps to remove the clip. Before crimping, and as shown in Figures 4 and 5, the projection 11 at the uppermost point of the clip effectively defines a small volume, by virtue of the shaping of the metallic strip which forms the clip 10. When the projection 11 is crimped or crushed, by the application of force from either side of it, the volume is effective reduced to zero or thereabouts. This has the effect of shortening the effective length of the clip, measured from end to end. It is this process that allows the clip 10 to be secured and retained in place. Figure 7f shows a side, partly sectional, view of the clip 10, cable 20 and cable tray 60 in the secured position, equivalent to the plan view shown in Figure 7e. The base of the clip 10 extends partly through the bed of the cable tray. When a relatively long run of cable is required, it can be placed loosely in position, with clips 10 introduced into the longs slots 61, as shown in Figure 7d (i.e. not yet crimped). Then, once the cable has been property dressed and routed, the individual clips 10 can be crimped in sequence, thereby locking the cable into position. If a clip 10 is to be removed after fitting, there are a number of means to achieve this. In a first technique, the crimped projection 11 can be sheared with a suitable tool, such as snips or pliers. Alternatively, a custom tool may be provided. A further use for the clip 10 is in the automotive sector. Electric Vehicles, EVs, require a significant length of electrical cabling, which is required to be fixed to the chassis of the vehicle. If the chassis is provided with slots as shown in Figure 7, then clips 10, may be used to secure the cabling in place. As with the cable tray of Figure 7, a particular advantage of such an arrangement is that access to both sides of the support structure is not required and the clip can be introduced and crimped from the cable side only of the support structure, be it a cable tray, vehicle chassis or other structure. In addition to the clip 10 being fire proof, it can also act as a fire stop. Prior art cable ties and the like can actively burn and so contribute to the problem. However, the close association of the clip with the cable sheath with which it is in contact can, serve to prevent fire from spreading along the cable. The clip 10 can be provided in a variety of sizes to accommodate cables of different sizes. The clip size may vary in over length (from hook to hook), material thickness, depth and still work according to the principles set out herein. A further advantage is that there is no waster associated with fitting a clip 10, since no trimming is required and all the material associated with a particular clip 10 is used each time. This reduces waste and any associated clearing up, as known with prior art devices. By use of an embodiment of the present invention, shortcoming associated with prior art techniques can be substantially avoided. A clip according to an embodiment of the invention is fireproof, non-sharp, easy and quick to fit, vibration proof, substantially tamper-proof and semipermanent (as defined previously). Its adoption in cable installations offers many advantages in addition to those mentioned above. It is, easy to manufacture in large quantities, requires little or no specialist training or tooling and can be deployed by any competent installer. Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A clip for securing a cable in position relative to a support structure, wherein the clip is a unitary member arranged to comprise a pair of opposed legs joined by a central portion, wherein each of the pair of opposed legs comprises a hook for engagement with the support structure and the central portion comprises a projection, whereby in the event of the projection being crimped, each respective hook engages securely with the support structure, thereby securing the clip, and hence the cable, in position, relative to the support structure.

2. The clip of claim 1 wherein the hook is provided with a lug for engagement with a corresponding aperture in the support structure, such that after crimping, the lug is securely retained in the corresponding aperture.

3. The clip of any preceding claim wherein the clip is formed from a metallic material.

4. The clip of claim 3 wherein the metallic material is stainless steel.

5. The clip of any preceding claim wherein the projection comprises a curved portionextending from a profile of the clip, the curved portion defining a volume, which, upon crimping, tends towards zero.

6. A support structure for use with the clip of any preceding claim, wherein the support structure comprises at least a first pair of slots arranged to receive the opposed legs of the clip and a second pair of slots, aligned with the first pair, the second pair being arranged to receive a lug provided on the clip.

7. The support structure of claim 6 wherein the support structure is a cable tray or a vehicle chassis.

8. A method of securing a cable using the clip of any preceding claim, comprising the steps of:a) positioning the cable relative to the support structure at a desired location;b) placing the clip atop the cable and loosely engaging the hooks with a feature ofthe support structure;c) crimping the projection such that the clip securely engages with the support structure and so holds the cable firmly in place.10

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